Question about mesh and accessories in animation. Please help

Hello! I am making one of those anime games that have anime characters as pets,
Today I decided to start making the actual characters and whilst getting the rigs, resizing them smaller, then getting the clothing placing it, everything was going fine up until I started placing hats which were meshes that’d i’d put in an accessory then place it in the model of the r6 char, when in studio they look great, however when in Roblox playing it glitches or moves…

I can’t anchor cos I plan on having these follow players while playing animations… Unless I can? I’m not sure.

Here are two pictures.

First top pic is in studio, second is actually in game.

Here’s another picture of how I usually put the mesh into an accessory thing and then into the model.